MCCC1 and Parkinson disease: Among the variants that form the PRS, three were nominally associated with PD status in the combined dataset (rs12637471 (MCCC1), rs34311866 (TMEM170-GAK-SGKQ) and rs356182 (SNCA) with p-values that range between 4.13 × 10−04 and 0.01 (Additional file 1: Table S1).